Carburetor for internal combustion engines



Aug. 9, 1966 G. R. MoRToN 3,265,374

CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Aug. 14, 1965 2'Sheets-Sheet l q" "f 56 a+ i f f 38 u a H a@ f/ Z af 5E Jy- L/ 68 v H-IT a l HI I ffs JO '32' I 4a l 38 Il I- ia Y( 30 .ze ,22, la /NVE/vrox?+0 @LE/VN P. MORTO/V Fig. 3 l

5V my@ i' AT A w5- Aug- 9, 1965 G. R. MORTON CARBURETOR FOR INTERNALCOMBUSTION ENGINES Filed Aug. 14, 1963 2 Sheets-Sheet 2 ibs,

' /M/E/vro/P 6L E/v/v P. MORTO/v Af E515 United States Patent O3,265,374 CARBURETR FR INTERNAL COM- BUSTIN ENGINES Glenn R. Morton,7025 Sarpy Ave., maha, Nebr. Filed Aug. 14, 1963, Ser. No. 302,078 113Claims. (Cl. 261-50) This invention relates to carburetors for internalcombustion engines and more particularly to a carburetor that willautomatically adjust to varying temperatures, atmospheric pressures, andengine manifold pressures.

Substantially, all internal combustion engines employ .a carburetor tomix the liquid fuel, such as gasoline, and air into an ignita'ble gas.Obviously the efficiency of the engine will depend on the proper mixtureof the air and liquid fuel. Most standard carburetors may be adjustedfor maximum eiciency for a given engine speed, and/or a givenatmospheric pressure. However, most carburetors have only one generaluse control, i.e., a buttery throttle valve in the air inlet conduit.This air flow is induced *by the engine piston suction and ishereinafter referred to as manifold pressure. The carburetors now ingeneral use have a gasoline float actuated valve in the fuel supply lineand a fuel pump to furnish the gasoline to the carburetor bowl.Obviously, such a mechanism is complicated, and does not automaticallyadjust to changing conditions.

Therefore, one of the principal objects of my invention is to provide acarburetor of simplified parts that will .automatically compensate forvarying conditions of pressures and temperatures.

A -further object of this invention is to provide a carburetor that willbalance its throttle position with the outside atmosphere Ias the enginemanifold pressure changes.

A still further object of this invention is to provide a carburetor thatwill automatically enrich the mixture o-f gasoline at critical enginestages of operation that require such additional fuel.

A still further object of this invention is to provide a carburetor thatwill successfully operate without a fuel pump or oat valve.

A still further object of this invention is to provide a carburetor thatprovides rapid engine acceleration.

A still further object of this invention is to provide a carburetor thatidles perfectly.

A still further object 4of this invention is to provide a carburetorthat is so eicient under all conditions that the pollution of the airfrom the engines exhaust is greatly reduced.

Still further objects of my invention are to provide a carburetor thatis economical in manufacture and durable 1n use.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, :andcombination, of the various parts of the device, whereby the objectscontemplated are attained as hereinafter more fully set forth,specifically pointed out in the claims, and illustrated in theaccompanying drawing, in which:

FIGURE 1 is a perspective view of my carburetor installed on an internalcombustion engine;

FIGURE 2 is an exploded perspective view of the throttle and needlevalve with a section cut away to illustrate the throttle construction;

FIGURE 3 is a vertical sectional view of the carburetor taken on line3-3 of FIGURE 1, and

FIGURE 4 is a vertical sectional View of the carburetor taken on line 44 of FIGURE 1.

In the drawings I have used the numeral to designate the intake manifoldof the internal combustion engine and to which my carburetor isassociated and into which Patented August 9, 1966 ICC it communicates.The main housing of my carburetor consists of a lower housing 12communicating with an upper housing 14, as shown in FIGURE 3. The lowerhousing 12 has an internal chamber 16 which is adapted to be incommunication with the manifold of the motor upon which the unit is tobe used, such as the opening 17. The upper housing 14 has an internalcylindrical chamber 18 which, except for the throttle to be describedhereafter, would be in communication with the chamber 16 in the lowerhousing 14. A vertical hollow tube 20 extends upwardly from the centerof compartment 16 and is in communication by means of conduit 22 withbore 44 in the outer :face of base housing 12.

A pressure regulator 26 has a cylindrical stud portion 28 which isreceived `within bore 24. The outer end of stud portion 28 terminates incup 30 having compartment 32 which receives oppositely disposed cups 34with registering compartment 36. Bolts 38 extend through the cups intobase housing 12. A fuel port 40 is in communication' with a source ofgasoline and communicates with chamber 32 by means of conduit 42 in thecup 30. The chamber 32 is in communication with the chamber 44 in theportion 28 by means of the conduit 46 in the cup 30. A hollow cap member48 in chamber 44 normally covers the inner end of conduit 46 and centerstem 50 slidably extends through the cup 30 into the compartment 32. Aspring 52 has one end connected to the stem of the cap 48 and its otherend connected toa set screw 54 threaded in the member 34. This springyieldingly holds the cap in a closed position and this yielding actionis adjustable by the set screw 54. The ladjustment yieldingly governsthe amount of gas pressure. The numeral 56 generally designates thevertically slidable throttle which is spool shaped in that it has adownwardly and outwardly extending lower skirt portion 58 and anupwardly and outwardly extending skirt portion 60. The skirt 60 slideswithin the cylinder bore 18 and a se-aling ring 62 is imposed betweenthe edge of the skirt 60 and bore 18. The area between the two skirts 58and 60 communicates with the outside atmosphere through the opening oropenings 64 that extend through the Wall of the upper housing 14. On thebottom center of the throttle 56 is a downwardly extending tube 66having its lower end portion slidable in the tube 20. A coil spring 68embraces the tube 20 having its lower end eng-aging the inside bottom ofthe lower housing and its upper end engaging the under side of thethrottle 56 for yieldingly holding the throttle in an upper position ofits sliding action. 'Ihe numeral 70 designates an upwardly extendingtube on the top center of the throttle 56. This tube 701 verticallyslides in a bearing 72 of the :upper housing part 14. A cap nut 74 isthreaded around the bearing 72. Threaded through the top of the cap nutis a thimble 76. The numeral 78 designates a needle valve having a tophead 80 slidable in the thimble 76, and a tapered stem portion 82,slidably extending through the bottom of the thimble and slidablythrough a hole 84 in the lower portion of the throttle below the tube70. Due to the location of the tube 66, the hole 84 will communicatewith its upper inside and the stem 82 of the needle valve will extendloosely into the tube 66. The numeral 86 designates a coil spring havingits lower end engaging the inside bottom of the thimble 76 and its otherend engaging the needle valve head 80 for yieldingly holding the needlevalve in an upper position of its movement. An adjustable hollow stopplug S8 is threaded into the top of the thimble 76 and above the head ofthe needle valve. The larea inside the upper housing and albove theupper skirt 60 of the throttle is designated by the numeral 90. Thenumeral 92 designates a passageway conduit connecting the manifold minuspressure area 16 with the area 90 above the throttle. The numeral 94designates a pilot valve imposed in the passageway conduit 92. Thisvalve 94 is actuated by the control rod 96. The numeral 98 designates asmall bleeder passageway communicating with the area between the upperand lower skirts of the throttle 56 and the passageway conduit 92. Thisopening passageway 9S is controlled by an adjustable threaded needlevalve 160 as shown in FIGURE 4. The numeral 102 designates a pluralityof radially extending passageways in the lower skirt 58 of the throttle.These passageways communicate with the inside 4bottom of the tube 70 andthe area 16 of the inside lower housing at the periphery of the skirtSS.

The practical operation of the device is as follows: The throttle 56 isvertically iioatable, but is controlled by engine suction andatmospheric pressures working in conjunction with the yieldable supportspring 63. The area between the two skirts of the throttle 56 is exposedto the outside atmosphere and in some experiments I permitted air toleak around the edge of the upper skirt 60 into the area 9x0. However,if there be any leakage, and with the valve 94 open, any such airleakage would be pulled into the engine intake manifold as fast as itcame in. When the engine is at idling speed the manifold vacuum willexist in the area 16, passageway conduit 92 and area 90 above thethrottle, thus pulling the throttle to an upper position of itsmovement. With the throttle in such an upward position, it will moreclosely embrace the needle valve stem 82, (which is tapered as itextends downwardly) and less gasoline will pass through the throttlepassageways 102. The course of the gasoline will lbe drawn by thesuction of the manifold pressure through the passageway 22, thencethrough the tube 20, thence through the tube 66, thence past the needlevalve and into the tube 7l?, thence through the passageways HB2 and theninto the air stream passing the periphery of the lower skirt of thethrottle. As the accelerator lever 96 is progressively moved to furtherprogressively close the valve 94 there will be less vacuum exerted onthe top of the throttle and the suction of the manifold pressure belowthe throttle will pull the throttle downwardly thereby increasing theflow of gasoline around the needle valve and through the opening 84. Ifthe accelerator rod is quickly actuated to increase engine speed, themanifold pressure is quickly dropped and there is la tendency Ifor thethrottle to quickly move downwardly and then objectionably bounceupwardly. This tends to cause a hesitation of the engine as the gasolinecatches up with the volume of air. To slow down the rapid downwardmovement of the throttle, a small spring loaded relier" valve 104 isimposed in a passageway N6 Connecting the area 16 with the passagewayconduit 92. Thus if any air were to rush down the conduit 92 after thevalve 94 were closed, the valve 104 would yieldingly permit the passageof air into the area I6 and slow the downward movement of the throttle.The chief source of air into the passageway conduit 94 and the area 90above the throttle is through the adjustable passageway opening 9S. TheO-ring 62 is -for preventing substantially all bleeding of air aroundthe periphery of the skirt 60 of the throttle. The adjustment of theneedle valve 100 is used to smooth out the carburetor for all speeds ofa given engine. When the throttle is moved downwardly by a minusatmospheric pressure in the area 16, the air will ow past theperipherial edge of the skirt 58 of the throttle and will suck gasolinefrom the passageways 102, and atomize it. The spring loaded needle valve78 may move upwardly or downwardly ve or six thousandths of an inch. Itwill raise with pressures of twenty-live inches or more. A ring groove110` may be cut around the periphery of the lower throttle skirt 58 anda plurality of spirally positioned grooves 112 extended thereto for theatmosphere to aid in drawing and atomizing the gasoline. From theforegoing it will be appreciated that the throttle is controlled by aminus pressure below it versus a controlled pressure above it. When thethrottle is in an up position, the area I6 is substantially closed tothe outside atmosphere and Ias it progressively lowers, thecommunication .between the are-a I6 and the outside atmosphereprogressively increases. No fuel pump is necessary. When the enginestarts, the vacuum will pull the needle valve down, thus eliminatinggasoline ooding. The action in conjunction with the throttle determinesthe proper richness of the gas relative to the air ratio. This automaticadjustment of parts insures the proper mixture at all speeds andatmospheric conditions. This proper mixture is maintained regardless ofthe throttle position.

Some changes may be made .in the construction and annangement yof mycarburetor for internal combustion engines without departing from thereal spiri-t and purpose of my invention, and it is my intention tocover by my claims, any modied forms of structure or use of mechanicalequivalents which may lbe reasonably included within their scope.

I claim:

1. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engine, j

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the entrance Ito said lower compantment,

an air inlet port in said housing communicating with the bore of saidhousing above the entrance to said lower compartment area,

a passageway extending through said throttle valve means adapted to haveone end in communication with a source of combustible fluid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one uid exit passageway in said throttle valve means having oneend operatively connected to the other end of said passageway of saidthrottle valve means and its other end communicating with the inside ofthe lower compartment area of said carburetor housing,

a conduit having one end communicating with the lower compartment area=of said carbure-tor housing and its other end communicating with theinside of the bore of said carburetor housing 'at a position abovethesaid throttle valve means,

and a manually controllable valve means imposed in said conduit.

2. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake .manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of :said housing andadapted to variably restrict the entrance yto said llower compartment,

an air inlet port in said housing communicating with the bore of saidhousing above the entranceto said lower compartment area,

a passageway extending through said throttle valve means adapted to haveone end in communication with a source of combustible fluid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one fluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating wi-th theinyside of the lower compartment area of said carburetor housing,

-a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

and -a passageway operatively connecting'the outside atmosphere with theinside of the bore of said carburetor at a Position above said throttlevalve means.

3. In Ia carburetor for internal combustion engines,

a carburetor housing having an lupper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an intennal combustion engine,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the lentrance to said lower compartment,

an yair inlet port in said housing communica-ting with the bore of saidhousi-ng above the entrance to said lower compartment area,

a passageway extending through .said throttle valve means adapted tohave one end in communication Vwith a source lof Icombustible fluid,

means mounting a needle valve stem extending into the p-assageway ofsaid throttle valve means,

at least one fluid exit passageway in said throtlle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment -area of said carburetor housing,

a condui-t having one end communicating with the lower compartment areayof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a -manually controllable valve means imposed in said conduit,

a passageway opera-tively connecting the outside atmosphere with theinside of the bore of said carburetor at `a .position above saidthrottle valve means,

and an .adjustable valve means in said last mentioned passageway.

4. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engin-e,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the entrance to said lower compartment,

an air inlet port in said housing communicating with the bore of saidhousing above the entrance to said lower compartment area,

a -passageway extending through said throttle valve means adapted tohave `one end in communication with a source of combustible uid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one fluid exit passageway in said throttle valve means havingone end yoperatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carburetor housing,

a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

a passageway operatively connecting the outside atmosphere with theinside of the bore of said carburetor at a position above said throttlevalve means,

an adjustable valve means in said last mentioned passageway,

and a means for yieldingly holding said throttle valve means in anupward position.

5. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the entrance to said lower compartment,

an air inlet port in said housing communicating with the upper area ofthe -bore of said housing above the entrance to saidlower compartmentarea,

.a passageway extending through said throttle valve means adapted tohave one end in communication with a source of combustible fluid,

means mounting a needle valve stem extending into the passageway Iofsaid throttle valve means,

at least one uid exit passageway in said throttle valve means having oneend operatively connected to the other end of said `passageway of saidthrottle valve means and its other end communicating with the inside ofthe lower compartment area of said carburetor housing,

a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

and a manually controllable Valve means imposed in said conduit.

6. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the the entrance to said lower compartment,

an air inlet port in said housing communicating with the bore of saidhousing above the entrance to said lower compartment area,

-a passageway extending through said throttle valve means adapted tohave one end in communication with a source of combustible uid,

means mounting a spring loaded needle valve stem extending into thepassageway of said throttle valve means,

at least one fluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carburetor housing,

a conduit having one end communicating with the lower compartment arealof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

and -a manually controllable valve means imposed in said conduit.

7. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engine,

throttle valve means slida-bly mounted i-n the bore of :said housing andadapted to variably restrict the the entrance to said lower compartment,

an air inlet port in ysaid housing communicating with the bore of saidhousing above the entrance to said lower compartment tarea,

4a passageway extending through said throttle valve means adapted tohave one end in communication with a source of combustible fluid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one fluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communica-ting with theinside of the lower compartment larea of said carburetor housing,

a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

a passageway operatively connecting the outside :atmosphere with theinside of the bore of said carburetor at a position above said throttlevalve means,

an adjustable valve means in said last mentioned passageway,

and a means for yieldingly holding said throttle valve means in anupward position;

said throttle valve means being in the general form of a spool having alower skirt portion and a spaced apart upper skirt portion.

8. In a carburetor for internal combustion engines,

va carburetor housing having 'an upper bore and a lower compartmentarea;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of :said housing andadapted to variably restrict the the entrance to said lower compartment,

van air inlet port in said 'housing communicating with the bore of saidhousing above the entrance to said lower compartment area,

a passageway extending through said throttle Ivalve means adapted tohave one end in communication with a source of combustible fluid,

means mounting a needle valve stern extending into the passageway ofsaid throttle valve means,

at least one Huid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carn buretor housing,

a conduit having one end `communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

a passageway operatively connecting the outside atmosphere with theinside of the bore of -said carburetor :at a position above saidthrottle valve means,

#an adjustable valve means in said last mentioned pas- `sageway,

and a means for yieldingly holding said throttle valve means in anupward position;

said throttle valve means being -in the general form f a 513001 having l19t/Ver skirt portion and a spaced apart upper skirt portion and withsaid combustible iiuid passageway or passageways extending through saidlower skirt portion.

9. In a carburetor for internal combustion engines,

a carburetor housing having au upper bore and a lower compartment area;Y

said lower compartment area yadapted to be in communication with theVintake manifold of an internal combustion engine,

throttle valve means :slidably mounted in the bore of said housing andadapted to var-i'ably restrict the the entrance to said lowercompartment,

an air inlet port in said housing communicating with v the bore of saidhousing above the entrance to said lower compartment tarea,

a passageway extending through said throttle valve means adapted to haveone end in communication with a Vsource of combustible fluid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one tluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carburetor housing,

l a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

a passageway 4operatively connecting the outside atmosphere wit-h theinside of the bore of said carburetor at a position above said throttlevalve means,

an adjustable valve means in said last mentioned passageway,

and a means for yieldingly hol-ding said throttle valve means in anupward position;

said throttle valve means 'being in the general form of :a spool haa/inga lowery skirt portion and a spaced apart upper skirt portion and withsaid combustible fluid passageway or passageways extending through saidlower skirt portion and exiting at the periphery of said lower skirtportion.

lil. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a .lower compartment area;

said lower compartment area adapted -to Ibe in communication with theintake manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the entrance to said lower compartment,

an air inlet port in said housing communicating with the bore of saidhousing above the entrance to said lower compartment area,

a passageway extending through said throttle valve means adapted to haveone end in communication with |,a source of combustible fluid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one fluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carburetor housing,

a `conduit having one end communicating with the lower ycompartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

a passageway operatively connecting the outside atmosphere with theinside of the bore of said carburetor at a position above said throttleValve means,

an adjustable valve means in said last mentioned passageway,

and a means for yieldingly holding said throttle valve means in anupward position;

said throttle valve means being in the general form of a spool having alower skirt portion and a spaced apart upper skirt portion and with saidcombustible iluid passageway or passageways extending through said lowerskirt portion .and exiting at the periphery of said lower skirt portion;

said lower skirt portion of said throttle valve means having anirregular periphery.

11. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore .and a lower compartment area;

said lower compartment area adapted to be in communication with theintake manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the entrance to said lower compartment,

an air inlet port in said housing communicating with the bore `of saidhousing above the entrance to said lower compartment area,

a passageway extending through said throttle valve means adapted to haveone end in communication with a source of combustible uid,

means mounting a needle valve stem extending into the pasageway of saidthrottle valve means,

at least one fluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carburetor housing,

a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above saidthrottle Valve means,

a manually controllable valve means imposed in said conduit,

a passageway operatively connecting the outside atmosphere with theinside of the bore of said carburetor at a position above said throttlevalve means,

an adjustable valve means in said last mentioned passageway,

la means for yieldingly holding said throttle valve means in an upwardposition,

and a passageway connecting the lower inside compartment area of saidcarburetor housing to said conduit at a point beyond said manuallycontrollable valve means.

12. In a carburetor for internal combustion engines,

a carburetor housing having an upper bore and a lower compartment area;

said lower compartment area adapted to lbe in cornmunication with theintake manifold of an internal combustion engine,

throttle valve means slidably mounted in the bore of said housing andadapted to variably restrict the the entrance to said lower compartment,

an air inlet port in said housing communicating with the bore of saidhousing `above the entrance to said lower compartment area,

a passageway extending through said throttle valve means adapted to haveone end in communication with a source of combustible uid,

means mounting a needle valve stem extending into the passageway of saidthrottle valve means,

at least one fluid exit passageway in said throttle valve means havingone end operatively connected to the other end of said passageway ofsaid throttle valve means and its other end communicating with theinside of the lower compartment area of said carburetor housing,

a conduit having one end communicating with the lower compartment areaof said carburetor housing and its other end communicating with theinside of the bore of said carburetor housing at a position above thesaid throttle valve means,

a manually controllable valve means imposed in said conduit,

a passageway yoperatively connecting the outside atmosphere with theinside of the bore of said carburetor at a position above said throttlevalve means,

an adjustable valve means in said last mentioned passageway,

a means .for yieldingly holding said throttle valve means in an upwandposition,

and a valve yregulated passageway connecting the lower insidecompartment area orf said canbu-retor housing to said conduit at a pointbeyond said manually controllable `valve means.

13. lIn a carburetor lfor internal combustion engines,

a carburetor haus-ing having a bore area and a compartment area,

said compartment area adapted to be in communication with the intakemanifold ot an internal combustion engine,

throttle valve means slidably mounted in the Ibore area of said housingand adapted to variably restrict the entrance to said compartment area,

an air inlet means in said housing communicating with the inside totlsaid housing `at a location lalbove the entrance to said compartmentarea,

a passageway vextending through said throttle valve means `adapted tohave ione end in communication with a source of combustible fluid,

means mounting a needle .valve stem extending into the passageway Aofsaid throttle wal've means,

:at least one uid exit passageway in said throttle valve means havingone end operatively connected to the other end ot said passageway ofsaid throttle valve audits other end communicating with said compartmentarea,

a conduit having one end communicating with said compartment area andits other end communicating with said bore area,

and a manually controllable valve means imposed in said conduit.

References Cited bythe Examiner UNITED STATES PATENTS 1,862,978 6/ 1932Norris 261--50 2,167,892 8/1-939 Kent et Ial 261-50 FOREIGN PATENTS435,768 9/ 1935 Great Britain. 515,040 11/19'319 Great Britain. 528,93911/1940 Great Britain.

HARRY B. THORNTON, Primary Examiner.

T. R. MILES, Assistant Examiner.

1. IN A CARBURETOR FOR INTERNAL COMBUSTION ENGINES, A CARBURETOR HOUSINGHAVING AN UPPER BORE AND A LOWER COMPARTMENT AREA; SAID LOWERCOMPARTMENT ARE ADAPTED TO BE IN COMMUNICATION WITH THE INTAKE MANIFOLDOF AN INTERNAL COMBUSTION EGINE, THROTTLE VALVE MEANS SLIDABLY MOUNTEDIN THE BORE OF SAID HOUSING AND ADAPTED TO VARIABLY RESTRICT THEENTRANCE TO SAID LOWER COMPARTMENT, AN AIR INLET PORT IN SAID HOUSINGCOMMUNICATING WITH THE BORE OF SAID HOUSING ABOVE THE ENTRANCE TO SAIDLOWER COMPARTMENT AREA, A PASSAGEWAY EXTENDING THROUGH SAID THROTTLEVALVE MEANS ADAPTED TO HAVE ONE END IN COMMUNICATION WITH A SOURCE OFCOMBUSTIBLE FLUID, MEANS MOUNTING A NEEDLE VALVE STEM EXTENDING INTO THEPASSAGEWAY OF SAID THROTTLE VALVE MEANS, AT LEAST ONE FLUID EXITPASSAGEWAY IN SAID THROTTLE VALVE MEANS HAVING ONE END OPERATIVELYCONNECTED TO THE OTHER END OF SAID PASSAGEWAY OF SAID THROTTLE VALVEMEANS AND ITS OTHER END COMMUNICATING WITH THE INSIDE OF LOWERCOMPARTMENT AREA OF SAID CARBURETOR HOUSING, A CONDUIT HAVING ONE ENDCOMMUNICATING WITH THE LOWER COMPARTMENT AREA OF SAID CARBURETOR HOUSINGAND ITS OTHER END COMMUNICATING WITH THE INSIDE OF THE BORE OF SAIDCARBURETOR HOUSING AT A POSITION ABOVE THE SAID THROTTLE VALVE MEANS,AND A MANUALLY CONTROLLABLE VALVE MEANS IMPOSED IN SAID CONDUIT.